The place were the magic happens: our workhouse, store, storage room and bureau

Coticule whetstones have been produced in this building (built in approx. 1865 and located in the Belgian Ardennes) for over 140 years.
The left part of the building (2 windows, 1 door and another window) is the main workplace (atelier). This is the place were the raw Coticule rocks are cut up into pieces and the end products (Coticule and BBW whetstones in all sort of sizes) are made.
The right part of the building (large arc window with a door in the middle) is our store, storage room and bureau space.

This atelier is also used to produce natural construction stones (like the ones our building is made off). These stones are stored in pallets in front of the building.

Our quarry is located at "Thier del Preu" (which means "height of Preu", Preu is a place name). Our extraction site is approx. 300 meters by 100 meters and we are at a depth of +/- 50 - 60 meters. The quarry is at a 2 km distance from our Atelier.
We need to extract approx. 2 tons of rocks to have 1 kg usable Coticule.

Main view of our quarry right after the winter of 2007-2008 (before the pumping started). The water has a height of +/- 10 meters.

Second view on the quarry (you can see my father Maurice, with the green jacket, together with a visitor standing on a rock which tops just above the water).

These Coticule plates have a thickness between 7 and 14 mm.
Sawing these plates is a very important job. It has to be done very careful to maximize the amount and size of Coticule plates. The raw Coticule rocks have cracks, black manganese spots, quartz blocks and other impurities in them so it requires a certain amount of experience and handiness to maximize the good Coticule!

This is the second step in the production of the Coticule whetstone.
We often get the question why it's done. The reason is simple! Coticule plates are so brittle that if such a plate falls of a height of 1 meter it will break into several pieces.
So we use black Brazilian or Portuguese natural schist as a base to glue the Coticule plates on. This way we have a sturdy whetstone that can handle several shocks!

This also is a very important job! This step is determining the final size of a Coticule whetstone (both rectangular and odd shaped stones!). The man doing this job has to look very careful at the Coticule because he needs to cut right through black lines or other faults in the Coticule and so maximizing the surface of Coticule without minor or major faults.

And these are the steps every single Coticule stone in the world has to pass before you can use it to sharpen your beloved straight razor!
Every Coticule stone is completely hand made at our atelier so every Coticule stone is a one of a kind!

The production of the BBW (Belgian Blue Whetstone) is the same except the gluing part.

I hope you liked this little explanation and if someone has further question, shoot away!

Coticules cannot be given a grit rating like one would do with other hones. That is because they work quite different than the majority of hones that abrade steel by means of small particles that scratch the steel away. Not Coticules. Mother Nature has loaded this exceptional rock with "garnets". Garnets are a kind of very hard crystals that are roughly round in a faceted way. They vary in size between 5 and 15 micron (in Coticules) and they abrade the steel in a very slow and gentle way. They do leave a scratch pattern, but it is very shallow and wavy. If you release the garnets from the stone and mix them with water, we call it "slurry". It is done by putting water on the hone and rubbing with another piece of Coticule till a milk-like substance has formed. In the slurry, the garnets are free to spin underneath the steel while honing, and this speeds up the process tremendously.

Many Cotilules have a cutting speed comparable to a 1K synthetic hone, when used with slurry. It has been reported
that Coticules with pinkish shades are often among the fastest Coticules, but you never know until you try. With a fast stone, the slurry will start show grayish discoloration almost immediately, from steel entering the mixture.

In slurry mode, such a Coticule is a superb hone for bevel setting and correction. The resulting bevel doesn't carry deep scratches and is ready for refinement on hones that can push the keenness a bit further. Coticules with slurry will prevent the edge from becoming sharper than a certain level. It is extremely sharp for a knife, but for shaving there still is some pulling sensation at that keeness level. At the same time, this behavior also prevents overhoning.

When used with water only (no slurry) Coticules are among the best finishing hones, but in that mode they offer hardly any keenness improvement. Their benefits lie into smoothing already keen edges. The resulting edges are nice to the skin and seem to discern very well between severing whiskers and catching skin. (although decent shaving technique remains important of course)

We found no real variance between the Blues, they all behave very closely the same. This is not so with Coticules. They show significant variance when used with slurry, but differences practically dissipate when they are used with water.

With slurry all coticules level off at a certain keenness that is only barely shaveable. When this level is reached, diluting the slurry every 10 laps with 2 drops of water till eventually all slurry is washed away over the course of 70 to 100 laps, dramatically improves the keenness, but the final outcome is a bit unpredictable.

The Belgian Blue with slurry is in absolute terms much slower than the coticule.

The Belgian Blue with slurry also levels off at a certain keenness, but this keenness is sharper than that left by the coticule with slurry.

The diluting trick on the Blue works too, but to a lesser degree than on the Coticule.

The Blue with water only does hardly anything on hard razor's steel.

A Coticule, when used with water as a polisher or finisher, smooths out almost any edge, also those that are sharper than what can be achieved with the Coticule by itself. It will not refine the edge as such, only smooth out the previous scratch pattern and leave it there.

With a heavy slurry, a good coticule can easily do the work of a DMT-1200 for honing out small edge defects, at the cost of some rounding at the bevel tip. For all other use on razors the slurry must be kept thin. Slurry on the Blue must also be kept thin.

Controversial, but we stand by it: Belgian hones do not lend their unique properties form a very fine grit rate. They are unrivalled because they leave such shallow scratch patterns, left by their round honing garnets that create a wavy surface. As a result the edge is far less jagged than that of many synthetic hones. This also means that the edge of the Blue with its larger garnets is even less jagged than that of the Coticule, a capacity that explains the higher level of keenness left by the Blue with slurry than that left by the Coticule with slurry.[2]

Below is a list of some official vendors that currently offer Belgian Coticules and Blue whetstones. This list is neither comprehensive nor exhaustive, and SRP is not associated with either of these vendors. They have, however, been recommended by several SRP users.